/*
 * Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package java.io;

/**
 * The <code>DataOutput</code> interface provides
 * for converting data from any of the Java
 * primitive types to a series of bytes and
 * writing these bytes to a binary stream.
 * There is  also a facility for converting
 * a <code>String</code> into
 * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
 * format and writing the resulting series
 * of bytes.
 * <p>
 * For all the methods in this interface that
 * write bytes, it is generally true that if
 * a byte cannot be written for any reason,
 * an <code>IOException</code> is thrown.
 *
 * @author Frank Yellin
 * @see java.io.DataInput
 * @see java.io.DataOutputStream
 * @since JDK1.0
 */
public interface DataOutput {

  /**
   * Writes to the output stream the eight
   * low-order bits of the argument <code>b</code>.
   * The 24 high-order  bits of <code>b</code>
   * are ignored.
   *
   * @param b the byte to be written.
   * @throws IOException if an I/O error occurs.
   */
  void write(int b) throws IOException;

  /**
   * Writes to the output stream all the bytes in array <code>b</code>.
   * If <code>b</code> is <code>null</code>,
   * a <code>NullPointerException</code> is thrown.
   * If <code>b.length</code> is zero, then
   * no bytes are written. Otherwise, the byte
   * <code>b[0]</code> is written first, then
   * <code>b[1]</code>, and so on; the last byte
   * written is <code>b[b.length-1]</code>.
   *
   * @param b the data.
   * @throws IOException if an I/O error occurs.
   */
  void write(byte b[]) throws IOException;

  /**
   * Writes <code>len</code> bytes from array
   * <code>b</code>, in order,  to
   * the output stream.  If <code>b</code>
   * is <code>null</code>, a <code>NullPointerException</code>
   * is thrown.  If <code>off</code> is negative,
   * or <code>len</code> is negative, or <code>off+len</code>
   * is greater than the length of the array
   * <code>b</code>, then an <code>IndexOutOfBoundsException</code>
   * is thrown.  If <code>len</code> is zero,
   * then no bytes are written. Otherwise, the
   * byte <code>b[off]</code> is written first,
   * then <code>b[off+1]</code>, and so on; the
   * last byte written is <code>b[off+len-1]</code>.
   *
   * @param b the data.
   * @param off the start offset in the data.
   * @param len the number of bytes to write.
   * @throws IOException if an I/O error occurs.
   */
  void write(byte b[], int off, int len) throws IOException;

  /**
   * Writes a <code>boolean</code> value to this output stream.
   * If the argument <code>v</code>
   * is <code>true</code>, the value <code>(byte)1</code>
   * is written; if <code>v</code> is <code>false</code>,
   * the  value <code>(byte)0</code> is written.
   * The byte written by this method may
   * be read by the <code>readBoolean</code>
   * method of interface <code>DataInput</code>,
   * which will then return a <code>boolean</code>
   * equal to <code>v</code>.
   *
   * @param v the boolean to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeBoolean(boolean v) throws IOException;

  /**
   * Writes to the output stream the eight low-
   * order bits of the argument <code>v</code>.
   * The 24 high-order bits of <code>v</code>
   * are ignored. (This means  that <code>writeByte</code>
   * does exactly the same thing as <code>write</code>
   * for an integer argument.) The byte written
   * by this method may be read by the <code>readByte</code>
   * method of interface <code>DataInput</code>,
   * which will then return a <code>byte</code>
   * equal to <code>(byte)v</code>.
   *
   * @param v the byte value to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeByte(int v) throws IOException;

  /**
   * Writes two bytes to the output
   * stream to represent the value of the argument.
   * The byte values to be written, in the  order
   * shown, are:
   * <pre>{@code
   * (byte)(0xff & (v >> 8))
   * (byte)(0xff & v)
   * }</pre> <p>
   * The bytes written by this method may be
   * read by the <code>readShort</code> method
   * of interface <code>DataInput</code> , which
   * will then return a <code>short</code> equal
   * to <code>(short)v</code>.
   *
   * @param v the <code>short</code> value to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeShort(int v) throws IOException;

  /**
   * Writes a <code>char</code> value, which
   * is comprised of two bytes, to the
   * output stream.
   * The byte values to be written, in the  order
   * shown, are:
   * <pre>{@code
   * (byte)(0xff & (v >> 8))
   * (byte)(0xff & v)
   * }</pre><p>
   * The bytes written by this method may be
   * read by the <code>readChar</code> method
   * of interface <code>DataInput</code> , which
   * will then return a <code>char</code> equal
   * to <code>(char)v</code>.
   *
   * @param v the <code>char</code> value to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeChar(int v) throws IOException;

  /**
   * Writes an <code>int</code> value, which is
   * comprised of four bytes, to the output stream.
   * The byte values to be written, in the  order
   * shown, are:
   * <pre>{@code
   * (byte)(0xff & (v >> 24))
   * (byte)(0xff & (v >> 16))
   * (byte)(0xff & (v >>  8))
   * (byte)(0xff & v)
   * }</pre><p>
   * The bytes written by this method may be read
   * by the <code>readInt</code> method of interface
   * <code>DataInput</code> , which will then
   * return an <code>int</code> equal to <code>v</code>.
   *
   * @param v the <code>int</code> value to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeInt(int v) throws IOException;

  /**
   * Writes a <code>long</code> value, which is
   * comprised of eight bytes, to the output stream.
   * The byte values to be written, in the  order
   * shown, are:
   * <pre>{@code
   * (byte)(0xff & (v >> 56))
   * (byte)(0xff & (v >> 48))
   * (byte)(0xff & (v >> 40))
   * (byte)(0xff & (v >> 32))
   * (byte)(0xff & (v >> 24))
   * (byte)(0xff & (v >> 16))
   * (byte)(0xff & (v >>  8))
   * (byte)(0xff & v)
   * }</pre><p>
   * The bytes written by this method may be
   * read by the <code>readLong</code> method
   * of interface <code>DataInput</code> , which
   * will then return a <code>long</code> equal
   * to <code>v</code>.
   *
   * @param v the <code>long</code> value to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeLong(long v) throws IOException;

  /**
   * Writes a <code>float</code> value,
   * which is comprised of four bytes, to the output stream.
   * It does this as if it first converts this
   * <code>float</code> value to an <code>int</code>
   * in exactly the manner of the <code>Float.floatToIntBits</code>
   * method  and then writes the <code>int</code>
   * value in exactly the manner of the  <code>writeInt</code>
   * method.  The bytes written by this method
   * may be read by the <code>readFloat</code>
   * method of interface <code>DataInput</code>,
   * which will then return a <code>float</code>
   * equal to <code>v</code>.
   *
   * @param v the <code>float</code> value to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeFloat(float v) throws IOException;

  /**
   * Writes a <code>double</code> value,
   * which is comprised of eight bytes, to the output stream.
   * It does this as if it first converts this
   * <code>double</code> value to a <code>long</code>
   * in exactly the manner of the <code>Double.doubleToLongBits</code>
   * method  and then writes the <code>long</code>
   * value in exactly the manner of the  <code>writeLong</code>
   * method. The bytes written by this method
   * may be read by the <code>readDouble</code>
   * method of interface <code>DataInput</code>,
   * which will then return a <code>double</code>
   * equal to <code>v</code>.
   *
   * @param v the <code>double</code> value to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeDouble(double v) throws IOException;

  /**
   * Writes a string to the output stream.
   * For every character in the string
   * <code>s</code>,  taken in order, one byte
   * is written to the output stream.  If
   * <code>s</code> is <code>null</code>, a <code>NullPointerException</code>
   * is thrown.<p>  If <code>s.length</code>
   * is zero, then no bytes are written. Otherwise,
   * the character <code>s[0]</code> is written
   * first, then <code>s[1]</code>, and so on;
   * the last character written is <code>s[s.length-1]</code>.
   * For each character, one byte is written,
   * the low-order byte, in exactly the manner
   * of the <code>writeByte</code> method . The
   * high-order eight bits of each character
   * in the string are ignored.
   *
   * @param s the string of bytes to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeBytes(String s) throws IOException;

  /**
   * Writes every character in the string <code>s</code>,
   * to the output stream, in order,
   * two bytes per character. If <code>s</code>
   * is <code>null</code>, a <code>NullPointerException</code>
   * is thrown.  If <code>s.length</code>
   * is zero, then no characters are written.
   * Otherwise, the character <code>s[0]</code>
   * is written first, then <code>s[1]</code>,
   * and so on; the last character written is
   * <code>s[s.length-1]</code>. For each character,
   * two bytes are actually written, high-order
   * byte first, in exactly the manner of the
   * <code>writeChar</code> method.
   *
   * @param s the string value to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeChars(String s) throws IOException;

  /**
   * Writes two bytes of length information
   * to the output stream, followed
   * by the
   * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
   * representation
   * of  every character in the string <code>s</code>.
   * If <code>s</code> is <code>null</code>,
   * a <code>NullPointerException</code> is thrown.
   * Each character in the string <code>s</code>
   * is converted to a group of one, two, or
   * three bytes, depending on the value of the
   * character.<p>
   * If a character <code>c</code>
   * is in the range <code>&#92;u0001</code> through
   * <code>&#92;u007f</code>, it is represented
   * by one byte:
   * <pre>(byte)c </pre>  <p>
   * If a character <code>c</code> is <code>&#92;u0000</code>
   * or is in the range <code>&#92;u0080</code>
   * through <code>&#92;u07ff</code>, then it is
   * represented by two bytes, to be written
   * in the order shown: <pre>{@code
   * (byte)(0xc0 | (0x1f & (c >> 6)))
   * (byte)(0x80 | (0x3f & c))
   * }</pre> <p> If a character
   * <code>c</code> is in the range <code>&#92;u0800</code>
   * through <code>uffff</code>, then it is
   * represented by three bytes, to be written
   * in the order shown: <pre>{@code
   * (byte)(0xe0 | (0x0f & (c >> 12)))
   * (byte)(0x80 | (0x3f & (c >>  6)))
   * (byte)(0x80 | (0x3f & c))
   * }</pre>  <p> First,
   * the total number of bytes needed to represent
   * all the characters of <code>s</code> is
   * calculated. If this number is larger than
   * <code>65535</code>, then a <code>UTFDataFormatException</code>
   * is thrown. Otherwise, this length is written
   * to the output stream in exactly the manner
   * of the <code>writeShort</code> method;
   * after this, the one-, two-, or three-byte
   * representation of each character in the
   * string <code>s</code> is written.<p>  The
   * bytes written by this method may be read
   * by the <code>readUTF</code> method of interface
   * <code>DataInput</code> , which will then
   * return a <code>String</code> equal to <code>s</code>.
   *
   * @param s the string value to be written.
   * @throws IOException if an I/O error occurs.
   */
  void writeUTF(String s) throws IOException;
}
